Incandescent lamp and socket



Patented Nov. 3,1896. [g1

INVENTOR (No Model.)

A. SWAN. INGANDESGENT LAMP AND SOCKET.

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UNITED STATES PATENT "FFICE.

ALFRED SXVAN, OF NEXV YORK, N. Y.

INCANDESCENT LAM P AND SOCKET.

SPECIFICATION forming part of Letters Patent No. 570,517, dated November 3, 1896. Application filed January 23, 1896. Serial No. 576,537. (No model.)

To all whmn it may concern.-

Be it known that I, ALFRED SWAN, a subject of the Queen of Great Britain, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Incandescent Lamps and Sockets, of which the following is a full, clear, and exact description.

This invention relates to the bases and sockets for incandescent electric lamps, the

Fig. 4. Fig. 7 is a section through line y y of Fig. 5. Fig. Sis a detail of the key-switch.

A represents the lamp, and B the lamp-base. The base is a shell or cup of porcelain fitting over the neck or wired end of the lamp.

Whereas the bases of all incandescent electric lamps as now manufactured are cemented or otherwise fastened to the lamp, so as practically to become an inseparable part thereof, according to this invention the base is a removable and interchangeable fitting admitting of repeated and continuous use.

The lateral groove a is formed in the neck of the lamp, and further indentations or depressions a are made in this groove at diametrically opposite points. A ring or band ct, formed of brass, encircles the neck of the lamp, covering the groove Q The purpose of this groove is toreceive cement by means of which the ring is held in its place, the indentations 6L3 counteracting the tendency of the cement to move when under strain, while perforations c in the brass ring similarly serve to key the latter firmly to the cement. In addition to the perforations a the brass ring is provided with two or more threaded holes a These are to receive screws by which the porcelain base is fastened upon the lamp-neck, the said screws passing through holes or slots a formed in the porcelain for this purpose.

Besides the great saving due to the repeated usage of the same base, there is also inherent in this plan the advantage that the lamps themselves may be made and finished with ring attachment all exactly alike, and may so be stored, the porcelain base only being connected therewith when the shipping-order calls for it and the required type of base is known.

One of the numerous objections to the prevailing method of attaching the base to the lamp is the not infrequent destruction of the lamp-wires by electrolytic action due to the contact of the latter with damp cement. Obviously this cause of failure would be impossible were the method adopted as here described.

The great reduciion in expenditure which this method of attachment makes possible would justify a superior article in point of finish and appearance, and this might be had at a cost very slightly, if any, beyond that of the present ungainly and in every respect unsatisfactory appendage. lVithin the thickness forming the bottom of this porcelain cup and in the center of its outer surface or disk a cylindrical recess 1) is provided, into which recess is fitted a shell I), of thin sheet metal,

with a thread rolled thereon, having a flange b around its open end and tongues b at its opposite end, these tongues being a portion of the bottom of the shell out through the center and turned downward. The flange b of the shell is hexagonal in shape and fits into and rests upon a countersink of corresponding shape around the margin of the recess in the porcelain. The tongues aforesaid pass through slits provided for this purpose in the bottom of the recess and are clenched or laid over against its under surface, so the piece is fastened in place in a manner calculated to prevent its movement when under strain; or, instead of the slits and tongues, the recess in the porcelain may go clear through and themetal shell be fastened therein by upsetting its lower or inner end, (after the manner of a cartridge-case,) as shown at 19 onto a shoulder formed in the porcelain for this purpose. The threaded metal shell is connected with one of the wires Ct of the lamp, this wire passing through a hole in the flange of the shell and being attached thereto by solder or other means. The other electrical connection between the lamp and base is by means of an annular band or rim 1), of thin sheet metal, circumscribin g and fitting over a relieved portion of the outer face or disk of the base. The other wire, c, of the lamp passes through a hole near the outer rim of the porcelain disk and is soldered at that point to the side of the aforesaid metal band.

Fig. 5 illustrates a lamp-socket adapted to the above-described form of base. Here again the employment of porcelain is a special feature of myinvention. The bed or block 0, to which the electrical circuits are affixed and by which they are insulated, is of porcelain, as are also the walls 0, forming the receptacle for the base of the lamp. Thus the socket is so far an integral piece. Two circular-shaped vertical apertures c and c are formed in the solid bottom of the receptacle, (one in the center and one near the circumference,) and lateral piercings c intercept these vertical apertures. Fitting into these apertures are metal blocks or posts 0 and c of corresponding shape and depth with the former, each block having a vertical hole through its center for passage of a wire lead and a transverse threaded hole for a threaded pin 0, which holds the post in place, as well as for a binding-screw 0 with which to tighten upon the wire which passes through it. The pin and screw enter the lateral piercing 0 When dropped into place, these blocks abut against a shoulder formed in the porcelain at the upper end of the aperture, and thus the lateral holes in the porcelain and the metal blocks, respectively, are brought to the same level. The central metal post is prolonged, so that its lower end projects into the well of the socket. This prolonged end or nipple is threaded to engage with the thread of the shell 1) within the recess in the face of the lamp-base, and so it makes electrical connection therewith. To the foot of the metal post occupying the outer vertical recess in the porcelain bottom of the socket a spring (Z is riveted. This spring is of sheet metal, preferably of ring form and slightly raised above the floor of the receptacle. It constitutes the other electrode of the socket, and by its means, when the lamp is screwed home and the metal rim b of its base is pressed against said spring the electric circuit is completed. Two vertical grooves or channels e c on the outer face of the receptacle at points diametrically opposite and stopped short a certain distance from its under lip provide for the attachment of a shade-carrier.

The foregoing applies to a keyless form of socket. For the key or switch form the following modificationsare made: the ringspring cl is bent upward from the point where it is riveted to its metal post, occupying in its bent form a trough or depression provided for this purpose in the bottom of the porcelain receptacle. A U-shaped metal bridgepiece f passes around this spring at its high est point diametrically opposite the centers of the metal posts 0 and c and is secured in its place by a screw passing into it through the porcelain bottom. A key-shaft 7; passes through a slot in the side of the porcelain receptacle and through holes in the upright of the metal bridge-piece. Between the arms of this bridge piece a rectangular oblong block or cam g, with an elongated slot g in its side, is slid upon the key-shaft, and a steel pin 9 passes through another opening in the block and through the key-shaft, from which its ends project slightly. \Vhen the keyshaft is turned, this shaft gives motion to the cam, and when therefore the lamp is screwed home and the key is turned so as to bring the cam into an upright position the cam will be in contact at its lower end with the annular metal rim b on the lamp-base, while its upper end will press the ring'spring d in. the socket and so complete the electrical circuit. The elongated slot in the side of the camblock provides for irregularities of construction and insures good electrical contact, for the block will assume an intermediate position between the contact on the lamp-base and the ring-spring in the socket and will bear with equal force against each of them.

When the key is turned to open the circuit, it first has a short motion independent of the cam. As soon as the cam has been turned sufficiently to carry its diagonally opposite corners beyond the center the spring acts upon it and throws it quickly out of contact with itself and with the metal rim on the base of the lamp. This quick movement is promoted by the lost motion provided between the cam and the shaft.

As new ordinarily constructed, the ends of the bridging-piece carrying the key'shaft are separated by the full diameter of the socket, an elongated hole or slot in one of these ends providing for inequalities. By having the slot within the cam-block itself I am enabled to bring the ends of the bridging-piece much nearer together, thus compacting the mech anism, while at the same time the central part of the socket-block is left free for the attachment of any form of center contact.

To enable this socket to be attached to an electrolier or other rigid fixture, my invention contemplates the use of stamped and drawn metal pieces, as follows: One of the pieces is the stamped shell or cap 1, Fig. 5, having a rolled thread on the flange t', forming its lowest and widest diameter, and having a groove t" around the under side of its smallest diameter or neck and indentations i at diametrically opposite points on the out side surface of this neck. Two semicircular stamped pieces j, of thick sheet metal, are placed within the neck and resting upon the flange or shoulder formed by the groove. These pieces are for the purpose of stiffening or reinforcing the neck, and one of them has in it a threaded hole j for the screw by which the fitting is tightened upon the electrolier. A drawn flanged shell or'bushing of sheet metal m, having a suitable thread rolled therein, is introduced within the circle formed by the semicircular pieces, its flange resting on the upper edge of those pieces somewhat below the level of the edge of the shell forming the outer case of the neck. Finally, this upstanding edge or lip of the neck is laid over and clenched by indents upon the flange of the threaded shell, and the nozzle-piece for attachment to an electrolier is complete. Another way of reinforcing the nozzle is illustrated in the detached view of Fig. 5.

The neck is drawn to form two concentric cylinders, one within the other, and the space between them is filled with soft solder. The inner cylinder may then be threaded to connect with the fixture.

The other piece or complementary part to that just described consists of a ring Z of stamped sheet metal, with a shoulder on its under side, and on its upper rim or flange a rolled thread corresponding in pitch with that on the flange of the nozzle-piece, so that these two pieces (the nozzle-piece and the tightening-ring) may engage by means of the thread on their respective flanges.

The nozzle-piece being first attached to the electrolier, the electrical connections with the terminals within the porcelain piece are made, then the tightening-ring is slipped over and coupled with the nozzle-piece, and by the act of screwing these pieces together the shoulder on the under side of the tighteningring brings 'up against a shoulder on the upper edge of the porcelain body formed there for that special purpose, and so the socket is solidly and firmly bound together.

Instead of a separate tightening-ring the ring as here described may be one with and form part of a metallicouter case or shell, instead of the porcelain walls, as hereinabove described.

An important feature of my invention is in the use of porcelain or other suitable insulating material for all parts of the lamp base and sorket except such portions as must be metallic to carry the current, and by thus constructing these parts the liability to short circuits is very small and precautions to insulate the shells are unnecessary.

Having thus described my invention, I

flanges on its extremities resting against shoulders on the insulating-cup; substantially as described.

3. An incandescent-lam p base consisting of a cup made of insulating material having a cylindrical cavity or perforation formed centrally in its lower end, in combination w th a cylindrical metallic threaded shell fitting into said cavity or perforation and provided on one end with a polygonal flange fitting into a correspondingly-shaped countersink around the edge of the cavity in the cup; for the purpose set forth.

4. An incandescent-lamp socket having a body or shell of insulating material in the shape of a cup, a central metallic post projecting from the bottom of the cup, and an annular spring-contact surrounding said post in combination with a lamp-base consisting of a cup made of insulating material provided on its lower end only with contact-pieces adapted to connect respectively with said post and spring, the insulating-walls of the base being surrounded by the insulating-walls of the socket.

5. In an incandescent-lamp socket, a block or body of insulating material provided with a hole in which a metallic post or block is located, said post having a longitudinal passage for the conducting-wire, and the body of insulating material being further provided with a hole laterally intersecting the other, and two screws located in said lateral hole, one of which holds the post in place, and the other binds the conducting-wire, substantially as described.

0. In an incandescent-lamp socket, a cylindrical shell closed by a disk across one end and made integrally of insulating material, said disk being the thicker on one side than on the other thereby forming a depression in one side of the bottom of the shell, in combination with a metallic post located in a perforation in the thicker side of the bottom, a ringspring secured to the end of the post and com forming in general shape to the depressed bottom of the shell and a key-shaft projecting through the shell and carrying a contactblock adapted to engage with the ring; substantially as described.

7. In an incandescent-lamp socket, the combination of a key-shaft, a circuit-closin g block carried thereby the block having a slot through which the shaft passes and two contact-pieces with which the ends of the block hole for the tighteningscrew, and a threaded bushing secured inside of the neck; substan tially as described.

9. The combination with an incandescent- In testimony whereof I subscribe my siglainp socket provided with an. exterior bead nature 1n presence of two wltnesses. around one end, of a threaded ring Z surrounding the socket and held in place by said bead, ALFRED SVAN. and a cap threaded to said ring and provided Vitnesses:

with means for attachment to a fixture, sub- FRANK S. OBER,

stantially as described. WM. A. RosENBAUM. 

